Recyclability of Polystyrene/Clay Nanocomposites

PS/organo-modified clay (5% w/w) nanocomposite has been subjected to a series of eight processing cycles in a twin screw extruder. The influence of multiple recycling on the properties of the nanocomposite was studied by following the changes in themorphology, the molecular structure, the melt flow index (MFI) and the thermal properties. The WAXS results indicate a strong intercalation of PS chains between silicate layers of the organoclay and the extent of intercalation appears to increase with increasing the number of cycles. The main effects of recycling are a reduction in molecular weight due to chain scission, although the occurrence of a crosslinking fraction is probable after 8 cycles. The thermal properties remain almost stable during reprocessing.